Cold fluids at cryogenic temperatures (e.g., less than −150° C.) pose special handling problems, principally because the temperature of such fluids may quickly cool any valve or coupler through which they flow. When such a coupler is used to transfer a cryogenic fluid, freeze-up problems may occur if the transfer takes place in a moist or high-humidity environment. Water within or immediately outside of the coupler may freeze, thereby impeding subsequent movement of mechanical parts within the coupler. Successive transfers from a single coupler to multiple receptacles may compound the problem.
Additionally, when de-coupling a coupler and receptacle, some amount of fluid venting to ambient is necessary. If the vented fluid is at high pressure, the venting may cause the coupler to forcefully eject from the receptacle.